Renewable energy resources have high volatility and therefore, they are difficult to predict and a predicted (calculated) schedule cannot be kept by the renewable power plant with desired accuracy.
In future, more and more independent power producers (PPS—power producer and supplier company) will enter the traditional grid (in Japan and elsewhere). They will rely heavily on renewable power plants. Grid stability (supply/demand balance) will be an important issue. New market mechanism (or already existing market mechanism that have not yet been exploited) will play an important role.
Patent literatures 1 to 5 disclose techniques of optimizing the operation schedule of a control-target device, such as an energy supplying device or an energy storage device. In patent literature 1, for example, an operation schedule of the control-target device is optimized in such a way that a predetermined evaluation index, such as the consumed energy or the energy cost, is minimized. The necessity of the re-scheduling is determined by comparing actual operation data with the control setting value based on the operation schedule at a preset timing.